I was downloading the file [
ifile.it] and it was stuck for awhile (couple of days). Entering the URL in the browser, it turns out that the file was removed.
It seems that the ifile.it plugin doesn't handle the case where the file was present at the start of the download and then subsequently removed at a later point.
If you try the URL now, it correctly identifies that the file was removed.
Not sure how you would debug/reproduce the problem.